Air relief for grease interceptors



Oct. 3, 1950 A. MATHEIS AIR RELIEF FOR GREASE INTERCEPTORS Filed July 19, 19 45 IN V EN TOR.

AARON MAT H El5 u luunviilliz;

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II II 111! Patented Oct. 3, 1950 AIR RELIEF FOR GREASE INTERCEPTORS Aaron Matheis, Michigan City, Ind., assignor to Josam Manufacturing Company, Cleveland, Ohio, a corporation of Delaware Application July 19, 1945, Serial No. 605,963

The present invention relates to an improved grease interceptor of the type comprising a closed top intercepting chamber into which waste water is directed for causing separation of grease and other light weight waste materials from the water in the chamber, the clarified water being discharged from the chamber through a passage leading from the bottom of the chamber upwardly to a sewer connection located at the normal water level in the chamber.

Heretofore, it has been a practice to provide an air relief passage between the area over the water in the chamber and the outlet passage of the chamber, which relief passage had its inlet at the top of the chamber and its outlet in the chamber outlet passage slightly below the normal static water level of the chamber. This arrangement enabled air to escape from the area above the water level when the water level was raised by an incoming waste water. By locating the outlet of the air passage below the water level in the interceptor outlet, an effective seal or trap was provided for preventing sewer gases from entering the intercepting chamber through the air relief passage.

This arrangement was not satisfactory, however, because there was considerable resistance to the escape of air through the relief passage due to friction in the passage and, principally because the water head over the outlet of the relief passage would increase considerably during surges of Waste water into the interceptor. The result was that pneumatic pressure developed above the liquid in the chamber and this pressuredepressed the water level below the normal static level and caused a surge of Water to discharge from the interceptor, thereby lowering the static water level below that for which the interceptor was designed. This reduction in the normal static level decreased the capacity and efficiency of the interceptor.

An object of the present invention is to provide an air relief passage between the interceptor chamber and the outlet passage of the chamber so located that the water head in the outlet has no effect on the movement of air through the relief passage, and which passage includes a trap against sewer gases that offers a minimum of resistance to the passage of water therethrough.

Another object of the invention is to provide an air relief passage between the interceptor chamber and the outlet of the chamber, which passage includes a water trap supplied with water from a source other than the water in the interceptor.

3 Claims. (Cl. 182-9) Other objects and advantages of the invention will be apparent from the following description of a preferred form of embodiment of the invention, reference being had to the accompanying drawing wherein:

Fig. 1 is a view in section of a grease interceptor embodying my invention; and

Fig. 2 is a fragmentary view in section, the section being taken on line 2-2 of Fig. 1.

Referring to the drawings, I have shown a grease interceptor indicated generally at 5, which interceptor is adapted to be connected in the drain of a sink or the like, from which water, laden with grease and other light weight waste material, is discharged. The interceptor removes light weight waste materials from the waste water and discharges the clarified water into a sewage system, for example. Although the invention may be embodied in different forms of interceptors, for the purposes of illustrating the invention, the interceptor 5 comprises a cubical intercepting chamber 6, which may be formed of iron or steel, and having an inlet connection T formed in the end wall 8 for connecting the chamber with the drain pipe of a sink, or other source of grease laden water. The outlet of the chamber 6 is formed at the end opposite the inlet, and comprises a pocket or offset 9 communicating with the chamber through an opening ID at the bottom of the end wall H. A vertically extending tube 12 leads from the pocket 9 upwardly to a horizontally extending sewer connection M. The pocket 9 and tube l2 form a trap leg through which water from the lower portion of the chamber 5 may be discharged into a sewer system. The static water level in the chamber is indicated by the line A, and this level obtains during the time no water is discharged into the interceptor. During fiow of water into the chamber 6, the level will be above the static level.

In the interceptor shown, the action of the water in the chamber is controlled by two sets of cascades I 6, only one set appearing in the drawings, formed in the bottom wall of the chamber and separated by a channel l1, and baffies 18 extending transversely of the chamber. This construction facilitates the separation of the light weight waste materials from the waste water.

The top of the chamber 6 is adapted to be closed by a removable cover plate 20 which is secured over the chamber by a turned over edge 2| engaging a flange 22 extending a ong the upper edge of wall 8, and a wing nut 23 threaded on a bolt 24 extending from the chamber walls and through an opening in the cover plate. Preferably, a gasket 25 is interposed between the cover plate '20 and the upper edges of the chamber walls for forming an air-tight seal between the walls and the cover plate. The construction thus far described is familiar to those skilled in the art.

To relieve the air from the area above the water level in the chamber 6 during the inflow of waste water, I have provided an air relief passage extending between the top portion of the chamber and the sewer connection I4. The outlet 30 of the air relief passage is located in the wall I l at the top of the chamber so that it will always be above the normal water levels in the chamber. From the inlet til the air passage is formed by a downwardly extending conduit 3i which opens into a basin 32, the lower end of conduit 31 being spaced from the bottom of the basin to allow for passage of air therethrough. The basin 32 opens into a chamber 313 and a conduit 34 leads from the lower portion of the chamber 33 and opens into the sewer connection M at the top thereof so that the air passage is formed having the outlet thereof above the water head in the outlet of the interceptor.

The basin 32 is adapted to be maintained filled with water fed thereto through a pipe 36 extending through an opening in the walls of the conduit 3i above the basin, and the pipe is preferably connected with a source of fresh water, not shown, and a small flow of water may be maintained into the basin. It will be understood, of course, that if the fresh water is obtained from a safe water supply system suitable steps should be taken to provide a connection to such a system that will preclude contamination of the safe water. Any excess from the basin will overflow into the sewer connection [4 through conduit 34.

Preferably, a clean-out opening 31 is formed in the top wall of chamber 33 and a plug 38 is threaded therein for affording access to the basin and chamber 33 for inspecting and cleaning, if necessary.

It will be apparent that the conduit 3| and basin 32 form a trap for preventing sewer gases from entering the chamber 6 through the air relief passage. Also, the air escaping through the relief passage is subject only to the resistance of the head of water in the basin 32, which is a minimum, and the head of water in the outlet of the chamber will have no effect on the resistance to movement of the air through the relief passage.

Thus, I have provided an improved grease interceptor in which the air over the liquid in the interceptor can be readily relieved from the chamber regardless of the water level in the interceptor outlet, and the air is relieved to the outlet of the interceptor through a gas trap that is operable independently of the discharge water of the interceptor. By the use of my invention, the water level will not be lowered by surging of waste water into the interceptor chamber and the proper water level may be maintained at all times in the interceptor.

Although I have described but one form of the invention, it is to be understood that other forms might be adopted, all falling within the scope of the claim which follows.

I claim:

1. In a grease interceptor, a closed top chamber adapted to receive grease-laden water, said chamber having an outlet comprising a conduit leading from adjacent the bottom of the chamber to an opening disposed below the top of the chamber whereby a body of liquid is maintained in said chamber; means forming an air passageway leading from the upper portion of the chamber to said conduit, said air passageway including a liquid trap disposed above the normal levels of the liquid in the chamber; and a liquid supply means for directing liquid into the trap independently of the water passing through the interceptor for removal of the grease therefrom.

2. In a grease interceptor, a closed top chamber adapted to receive grease-laden water, said chamber having an outlet comprising a conduitleading from adjacent the bottom of the chamber to an opening disposed below the top of the chamber whereby a body of liquid is maintained in said chamber; a pressure relieving means forming an air passageway leadingfrom the upper portion of the chamber to said conduit, said means including a liquid trap having an overflow substantially above the normal liquid level in the interceptor; and a fresh water connecting duct associated with the air passageway for directing liquid into the said trap independently of the liquid flowing through the interceptor.

3. In a grease interceptor, a closed top member adapted to receive grease-laden water, said chamber having an outlet comprising a conduit leading from adjacent the bottom of the chamber to an opening disposed below the top of the chamber whereby a body of liquid is maintained in said chamber; means forming an air passageway leading from the upper portion of the chamber to said conduit, said means including aliquid trap comprising an open top basin for containing a liquid, a tubular member extending into the basin below the upper edge thereof; and liquid supply means for directing liquid into said basin independent of the liquid flowing through the interceptor.

AARON MATI-IEIS.

REFERENCES CITED 7 The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,099,061 Gordon Nov. 16, 1937 2,268,854 Boosey Jan. 6, 1942 2,272,912 Heinkel l- Feb. 10, 1942 2,284,737 Hirshstein June 2, 1942 2,433,087 Boosey Dec. 23, 1947 2,453,219 Grum Nov. 9, 1948 

